From: Prarit Bhargava <prarit@redhat.com>
Date: Mon, 3 Aug 2009 11:07:27 -0400
Subject: [misc] cpufreq: don't set policy for offline cpus
Message-id: 20090803150609.27487.32103.sendpatchset@prarit.bos.redhat.com
O-Subject: [RHEL 5.5 PATCH] cpufreq: Don't set policy for offline cpus
Bugzilla: 511211
RH-Acked-by: Matthew Garrett <mjg@redhat.com>
RH-Acked-by: John Feeney <jfeeney@redhat.com>
RH-Acked-by: Danny Feng <dfeng@redhat.com>

Suspend/Resume fails on multi socket, multi core systems because the cpufreq
code erroneously sets the per_cpu policy_cpu value when a logical cpu is
offline.

This most notably results in missing sysfs files that are used to set the
cpu frequencies of the various cpus.

An example of this problem can be seen in the BZ.  I've also pushed this
upstream to the cpufreq list and will update the BZ with links to the
thread.

Resolves BZ 511211.

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 25cdd2c..a6199fe 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -801,6 +801,8 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
 
 	spin_lock_irqsave(&cpufreq_driver_lock, flags);
 	for_each_cpu_mask(j, policy->cpus) {
+		if (!cpu_online(j))
+			continue;
 		cpufreq_cpu_data[j] = policy;
 		per_cpu(policy_cpu, j) = policy->cpu;
 	}